Prosecutors say former coal company executive Don Blankenship has to head to prison on May 12, pending an appeal.

Prosecutors mentioned the ex-Massey Energy CEO's date to surrender to federal custody in a 4th U.S. Circuit Court of Appeals filing on Wednesday.

Blankenship was sentenced April 6 to the maximum penalties of a year in prison and a $250,000 fine for conspiring to willfully violate mine safety standards at Upper Big Branch Mine in West Virginia. A jury convicted him Dec. 3.

The coal mine exploded in 2010, killing 29 men.

Blankenship is appealing. He's also asking the higher court to stay free on his $1 million bond while his appeal continues. Otherwise, Blankenship's attorneys say he may serve much, or all, of his sentence before a decision is reached.